He said: “There is a lot in the press about the grid connection charges facing Scottish Power to close up Longannet but the fact is the grid connection charges have been the same for many years. But over the years there has been so much wind energy taking priority over coal and the reason Longannet is no longer earning enough to keep it running is down to the flawed government with their disgraceful windfarm policy. It is their own fault and Fergus Ewing has had a road to Damascus moment.

“The problem arises from the fact that when the national grid has to shed load it sheds the cheapest load, and coal is only half the price of wind so it shuts down the cheap, reliable generator and allows us to buy electricity from expensive generators.

“The national grid is commercially driven and they take actions but for their shareholders and will always shut down coal and gas first.”

A Scottish Government spokeswoman said: “The Scottish Government has a target of delivering the equivalent of at least 100% of gross electricity consumption from renewables by 2020. We are making significant progress with over 44% of gross consumption in Scotland met using renewable sources in 2013, accounting for 32% of total UK renewable electricity generation.

“Ministers have always been clear that renewables will form part of a wider, balanced electricity mix, with thermal generation continuing to play an important role.”

The national grid’s high voltage transmission lines mean that the cost of electricity is higher north of the border – further from highest demand.

It costs about £40m a year to keep Longannet connected to the national grid, while an equivalent power station in the south of England would receive a payment of £4m.